Resilient slip suspension means for hydraulic packer

ABSTRACT

A resilient mounting for the upper slip in a Hydraulic packer which holds the upper slip carrier and the slip carried thereby in retracted position out of contact with the upper packer head while running in the hole so that if the packer is stopped suddenly or the slip encounters an obstruction which tends to cause the slip to move downwardly in contact with the upper packer head, a spring in the suspension head will cause the carrier and the slip mounted thereon to move back into relaxed running position out of contact with the casing.

lJit e tates Tucker Inventor:

RESHLIENT SLIP SUSPENSION MEANS FOR HYDRAULIC PACKER Andrew J. Tucker, Dallas, Tex. Assigne'e: Dresser Industries, Inc., Dallas, Texv Filed: May 24, 1971 Appl. No.: 146,056

US. Cl. ..166/217 Int. Cl. ..E2llb 23/00 Field of Search ..166/l20, 121, 122,

References Cited UNITEDSTATES PATENTS 2/l948 Page, ...l66/2l2 l2/l970 Kilgore.... ....l66/l2l 10/1943 Page ..l66/2l2 Primary Examiner-James A. Leppink AttorneyRobert W. Mayer, Thomas P. Hubbard, Jr., Daniel Rubin, Raymond T. Majesko, Roy L. Van Winkle, William E. Johnson, Jr., Morgan L. Crow, Eddie E. Scott and Howard E. Moore [57] ABSTRACT 7 Claims, 4 Drawing Figures SHEET 2 OF 2 PATENIE mm x i i a M &

ATTOPNEY RESILIENT SLIP SUSPENSION MEANS FOR HYDRAULIC PACKER BACKGROUND OF INVENTION The improvement, which is the subject matter of this invention, is related to a hydraulic packer of the type disclosed in United States Letters Pat. No. 3,460,616 entitled Retrievable Packer with which is employed slips or gripping members like that disclosed in United States Letters Pat. No. 3,548,936 entitled Well Tools and Gripping Members Therefor, in which last named patent said slip members are disclosed in FIGS. 15A, 15B and 15C used in conjunction with a hydraulic packer of the general type to which this improvement is related.

A packer of the type with which this invention is employed is fully disclosed in co-pending application of Bobby L. Douglas filed May 24, 1971 under Ser. No. 146,027 entitled Floating Piston for Selective Hydraulic Packer, reference to which is made for all purposes.

In such packers, it has been the practice in the past to secure the upper slip in up position by a shear pin which was broken at the time of the unsetting of the packer. The shear pins held by the slip in up position so as to permit enough upward movement of the balance valve chamber to closethe balance valve upon setting the packer. In some instances the shear pins were accidentally sheared while running in the hole, allowing the slip assembly to drop down'which would result in not allowing enough movement of the balance valve chamber during the setting of the tool to close the SUMMARY OF INVENTION As disclosed herein the slip carrier is slidably disposed about the upper mandrel and is suspended by a spring in the slip control housing. The upper slip is slidably disposed on the slip carrier and is spring biased into vertical position. The slip is arranged to be tilted laterally with reference to the slip carrier to set the teeth thereon against the wall of the casing when the lower end of the slip engages the upper end of balance valve chamber to exert a longitudinal force thereagainst. If upon lowering the packer in the well, the packer or well string encounters an obstruction and suddenly stops, the momentum of the slip may cause the slip carrier to move downwardly against the spring on which it is suspended to a limited extent, but the spring will immediately relax after the impact to cause the slip carrier to move upwardly in the said control housing to return the slip to unset position, thereby preventing the slip from becoming inadvertently set to such an extent as to prevent the closure of the balance valve. 1

Upon unsetting the packer, an upward force is exerted on the tubing string to shear the lower shear pin (not shown) to release the packer and open the balance valve to allow the packer to be unset. ln exerting such upward pull on the tubing string the upper slip control housing moves upwardly about the slip carrier, compressing the spring on which it is mounted to solid condition, which allows sufficient stroke to open the balance valve before unsetting the slip. Continued upward movementof the upper slip control housing moves the slip carrier and the slip thereon upwardly to a sufficient extent to disengage same from the upper end of the balance chamber to allow the slip to move to a vertical position to unset same. After the slip is unset the spring on which the slip carrier is suspended forces the upper slip and slip carrier into up position out of engagement with the balance valve chamber for retrieving and the said spring will maintain the slip in up unset position upon retrieval of the tool and will move same to normal unset position after encountering impact on the way out of the hole in order to maintain the slip in the unset position.

DESCRIPTION OF DRAWINGS A suitable embodiment of the invention is shown in the attached drawings, wherein;

FIG. 1 is a partially sectionalized elevational view of the slip suspension assembly in conjunction with the balance valve in a hydraulic packer of the type indicated; showing the upper slip in unset condition as it would be lowered into the well;

FIG. 2 is a partially sectionalized elevational view of the slip suspension assembly with the slip in set position; I

FIG. 3 is a partially sectionalized elevational view of the slip suspension .assembly as it would appear while the packer is being unset by an upward pull on the tubing string; and;

FIG. 4 is a partially sectionalized elevational view of the slip suspension assembly as it would appear after the packer has been relaxed and is being retrieved from the well.

DESCRIPTION OF A PREFERRED EMBODIMENT Numeral references are employed to indicate the various parts shown in the drawings and like numerals indicate like parts in the various figures of the drawings.

The numeral 1 indicates a top sub or connection which is arranged to be threadedly engaged to a tubing section extending into the well to suspend the packer in the well and to allow fluid communication therethrough.

The tubular upper slip control housing 2 is threadedly suspended to the top connection 1. A resilient take-up ring 3 is disposed between the lower end of the top connection 1 and the split ring retainer 4. The spring retainer 4 is engaged in a slot extending about the upper end of the slip carrier 7 and provides an upper stop for the spring 5. The coil spring 5 is disposed about the slip carrier 7 and is abutted at its lower end against the cap 6 which is threadedly engaged to the lower end of the slip control housing 2.

The slip carrier 7 is slidably disposed about the upper mandrel 11 and is movable inwardly and outwardly with relation to the upper slip control housing 2 and is resiliently suspended on the spring 5. The slip carrier 7 has spaced shoulders 7a and 7b thereon providing a recessed area to prevent an internal bind on the slip when it is in the set position. The slip 8 is suspended on the lug 8e provided on the slip carrier in contact with shoulder 8f on the slip body and spring 9 is disposed against the outer wall of slip carrier 7 to maintain the slip in vertical position. Spring 9 is attached to slip body 8 by a cap screw 10.

The upper slip 8 is of the type disclosed and described in U. S. Pat. No. 3,548,936 to which reference is made. Said slip 8 has teeth and 8b at opposite outer ends thereof which are arranged to be moved into engagement with the inner wall of the casing 25 to anchor the packer in the well. An elongated slot 8c is provided in the wall of the slip carrier 7. The pivot pin 8d extends through said slot and is threadedly engaged to slip 8. The slip 8 is arranged to be tilted sidewise on the pivot pin 8d by reason of obliquely arranged passages at opposite ends of the slip. The slip is tilted when force is applied against the lower end thereof by engagement with the upper end of the balance valve chamber which slides same upwardly on the slip carrier 7 and tilts same laterally against the spring 9. When pressure is relieved from the lower end of the packer and it is allowed to drop back to running position as shown in FIG. 1 the spring 9 tilts the slip back to vertical position out of engagement with the wall of the casing.

The upper mandrel 11 is threadedly engaged to the top connection 1 and extends through the packer to provide fluid communication therethrough and a suspension means for the packer.

A threaded cap or head 12 is provided on the upper end of the balance valve chamber 19. A balance piston 13 is slidably disposed in the balance valve chamber 19 and has seals 14 and 15 on opposite sides thereof to seal against the inner surface of the balance chamber 19 and the outer surface of the mandrel 11. The balance valve 18 is secured to the mandrel 11 by means of a keeper ring 17 disposed in a slot extending about the mandrel 11 which is held in place and connected to the mandrel 11 by means ofa keeper ring 16 extending thereabout. A seal ring 18a is disposed about the upper end of the balance valve 18 and is slidably'engaged with the inner wall of the balance chamber 19 to provide a seal thereagainst.

Ports 19a are provided through the wall of the balance chamber 19 to provide communication with the area below the balance valve. when open to permit equalization of pressure across the packer while it is being run and retrieved.

The valve sub-seal assembly 20 comprises an outer metalic shell which rests on a shoulder 22a provided inside the seal housing 22. An elongated seal 20a is provided on the inner side of the seal assembly 20 and a seal 20b is provided on the outer side thereof to seal against the inner wall of the seal housing 22.

Upon the setting of the packer the balance chamber 19 moves upwardly to cause the lower end of the balance valve 18 to enter the space between the seal 20a and the outer wall of the mandrel 11 to close the valve and the ports 19a.

The packer body 24 extends through the packer rubbers (not shown) and a seal 23 is provided between the upper end thereof and the inner surface of the seal housing 22.

OPERATION AND FUNCTION The slip suspension assembly is made up with the packer and attached to a tubing string for lowering into the casing 25 and is in the position shown in FIG. 1 while it is being lowered.

In the event the packer or tubing string encounters an obstruction while traveling in the well to cause a vertical impact on the slip 8, the slip carrier 7 and slip 8 can move downwardly against the spring compressing the spring. After the impact the spring will relax and move the slip carrier and slip upwardly into a normal running position, thereby preventing the slip from encountering the balance chamber head 12 to set the slip. Upon reaching the position in the well wherein the packer is set, the slip 8 is set by actuating the hydraulic cylinder in the packer to set the packer in the manner described in the said co-pending application of Douglas. Upon setting the packer the balance chamber 19 moves upwardly with relation to the mandrel 11, closing the valve 18 and engaging the lower end of the slip 8 to set same against the casing 25 as shown in FIG. 2.

When it is desired to retrieve the packer from the well an upward pull is exerted on the tubing string to the top connection 1 in order to shear the shear screws at the bottom of the packer (not shown) to allow same to relax. The initial upward movement of the top connection 1 and the mandrel 11 causes the control housing 2 to move upwardly, compressing the spring 5 to solid condition (FIG. 3). Such upward movement of the mandrel 11 opens the valve 18, allowing equalization of pressure across the packer before the slip is released. Continued upward movement of the upper slip control housing 2 moves the upper slip carrier 7 and mandrel ll upwardly together to move the slip 8 out of engagement with the upper end of the slip carrier 7 to allow the slip to pivot to a vertical position out of engagement with the wall of the casing 25 to unset position. After the slip is unset the packer is relaxed for retrieval as shown in FIG. 4. The spring 5 maintains the upper slip carrier 7 and slip 8 thereon in up position during retrieval.

Having described my invention, I claim:

1. Means for suspending a slip to a well tool comprising: a tubular mandrel; a housing attached to the mandrel; a slip carrier slidably disposed about the mandrel, said slip carrier having a shoulder thereon and disposed within said housing; resilient means in the housing in contact with said shoulder suspending the slip carrier to said housing; a slip slidably disposed on the slip carrier below the housing; and a resilient take-up ring between the upper end of the slip carrier and the housing to control the movement of the carrier into the housmg.

2. Means for suspending a slip to a well tool comprising: a tubular mandrel; a housing attached to the mandrel; a slip carrier slidably disposed about the mandrel; resilient means in the housing suspending the slip carrier thereto; and a slip slidably disposed on the slip carrier below the housing, said housing comprising a skirtlike member in spaced relation to the mandrel; an inwardly extending shoulder at the lower end of the skirtlike member against which the lower end of the resilient member is positioned; and a shoulder on the upper end of the carrier providing a stop for the upper end of the resilient member.

3. The combination called for in claim 2 wherein the resilient member is a spring.

- 4. The combination called for in claim 1 wherein the slip is pivotally mounted on the slip carrier and is arranged to be tilted laterally by a force exerted against the end thereof; and spring means between the slip and the carrier to bias same to vertical position.

5. The combination called for in claim 4 with the addition of a member carried by the mandrel movably disposed thereabout and arranged to engage the end of the slip to exert force thereagainst to tilt same.

6. The combination called for in claim 5 wherein the member engageable with the slip to tilt same is a balance valve housing.

7. The combination called for in claim 4 with the addition of spaced shoulders on the slip carrier providing a recessed area thereon, the spring member being carried by the slip and engaged with the area between the said shoulders biasing the slip into vertical position.

4 i I III 

1. Means for suspending a slip to a well tool comprising: a tubular mandrel; a housing attached to the mandrel; a slip carrier slidably disposed about the mandrel, said slip carrier having a shoulder thereon and disposed within said housing; resilient means in the housing in contact with said shoulder suspending the slip carrier to said housing; a slip slidably disposed on the slip carrier below the housing; and a resilient take-up ring between the upper end of the slip carrier and the housing to control the movement of the carrier into the housing.
 2. Means for suspending a slip to a well tool comprising: a tubular mandrel; a housing attached to the mandrel; a slip carrier slidably disposed about the mandrel; resilient means in the housing suspending the slip carrier thereto; and a slip slidably disposed on the slip carrier below the housing, said housing comprising a skirt-like member in spaced relation to the mandrel; an inwardly extending shoulder at the lower end of the skirt-like member against which the lower end of the resilient member is positioned; and a shoulder on the upper end of the carrier providing a stop for the upper end of the resilient member.
 3. The combination called for in claim 2 wherein the resilient member is a spring.
 4. The combination called for in claim 1 wherein the slip is pivotally mounted on the slip carrier and is arranged to be tilted laterally by a force exerted against the end thereof; and spring means between the slip and the carrier to bias same to vertical position.
 5. The combination called for in claim 4 with the addition of a member carried by the mandrel movably disposed thereabout and arranged to engage the end of the slip to exert force thereagainst to tilt same.
 6. The combination called for in claim 5 wherein the member engageable with the slip to tilt same is a balance valve housing.
 7. The combination called for in claim 4 with the addition of spaced shoulders on the slip carrier providing a recessed area thereon, the spring member being carried by the slip and engaged with the area between the said shoulders biasing the slip into vertical position. 